Ben Carson speaks during an election night party in Baltimore. Photo / AP

Ben Carson, the retired neurosurgeon who briefly led the Republican presidential race before his campaign began an extended public implosion, will tell his supporters in a statement on Wednesday afternoon (local time) that he does not see a “path forward” and will not attend Thursday’s debate in Detroit, according to two Republicans familiar with his plans.

Carson, however, will not formally suspend his campaign. Instead, the Republicans said, he has decided to make a speech about his political future on Friday at the Conservative Political Action Conference in Maryland, just outside of Washington.

But the announcement will serve as an acknowledgement that Carson’s candidacy is all but over following a disappointing showing in the 11 states that held contests on Tuesday.

The decision follows months of candidate stumbles, staff infighting and strategy shifts derailing what had once appeared to be an unstoppable journey to conservative superstardom.

It also marks the coming departure of the only major African-American candidate in the 2016 presidential race.

Carson, 64, burst onto the political scene in early 2013 when, addressing the typically nonpartisan National Prayer Breakfast, he spoke about the dangers of political correctness, put forward the idea of a flat tax and criticised President Barack Obama’s health-care law. What made it stand out is that he did it right beside a steely-faced Obama.

That week, the Wall Street Journal ran an editorial titled “Ben Carson for President.” By August of that year, there was a “National Draft Ben Carson for President Committee.” Before he launched his presidential bid in this past May, the group had raised close to $16 million, gotten a half-million signatures encouraging Carson to run and had 30,000 active volunteers across the country, according to organisers.

The media whirlwind was hardly his first brush with fame. Before he took the conservative world by storm, Carson was famous for an up-from-his-bootstraps life story, from impoverished childhood to a high-profile neurosurgery career. He was, at 33, the youngest major division director in Johns Hopkins Hospital history, and he was the first pediatric neurosurgeon to successfully separate twins conjoined at the head. He wrote a best-selling book, “Gifted Hands,” about his life, which later became a television movie.

The same bluntness that catapulted him into contention in a year that favoured plain-spoken insurgents and outsider candidates earned him criticism as well. He found himself in political hot water for calling the Affordable Care Act the “worst thing that has happened in this nation since slavery,” saying the current-day United States is “very much like Nazi Germany” and predicting that allowing same-sex marriage could lead to legalised bestiality.

Even his political team admitted from the start that perhaps he needed to work on his messaging. “If I could create the Webster’s dictionary of words Dr. Carson could use in the campaign, there would be some words I’d leave out,” his former campaign chairman, Terry Giles, told The Washington Post before Carson officially jumped into the race in May. Later, when Donald Trump grabbed headlines, the usually mild-mannered Carson was urged to dial it up and take the mogul on more aggressively.

Carson resisted that advice as well. Until the end, he sought to offer himself to Republicans as a calm and steady hand, untouched by Washington.

“Many people told me that this business is corrupt, that it’s evil, that it’s how it’ll always be,” Carson said in a phone interview on Monday. “But I don’t believe that we have to accept that. We should rail against that, fight against it, and get something that’s decent and inspirational.”

His performance may have played a role in his political undoing. Even as his “politically incorrect” style played well in places with staunchly conservative bases, his apparent unfamiliarity with many policy fundamentals, particularly on national security issues, made some voters wary.

His support dropped precipitously in the weeks after two high-profile terrorist attacks, bringing him from second place just behind Trump to fourth or fifth place in most national polls.

“Unfortunately, Paris happened. San Bernardino happened,” he told The Postearlier this year. “Somehow the narrative has been projected that if you’re soft-spoken and mild-mannered, there is no way you can deal with terrorism, with national security, that you’re not a strong person.”

It wasn’t just Carson’s often unfiltered and unseasoned approach that cost him; his advisers’ did as well, as internal feuds played out publicly, and candidate and campaign deficits were spotlighted in unusually detailed media admissions by some staffers and advisers.

Disagreements within the campaign’s highest ranks broke out into the open on numerous occasions, highlighting a persistent and sharp division between Armstrong Williams – Carson’s longtime business manager, who was not formally part of the campaign – and Barry Bennett, the Republican operative who led it.

As Carson fell from top-tier status, he publicly blamed campaign aides for his drop in the polls – calling some of them overpaid and ineffective – and vowed a staff shake-up in an interview arranged by Williams without Bennett’s knowledge. Carson backtracked hours later, but within days, several of his most experienced campaign hands, including Bennett, had resigned.

A new campaign chairman was named: retired Army Maj. Gen. Robert Dees – previously a Carson policy adviser who, like the candidate himself, had never before been involved in a political campaign.

The departure of a string of senior aides didn’t end the behind-the-scenes drama. Within weeks, reporters were sent a list of the only staffers they were to contact for campaign comment and for candidate interview requests – a list that pointedly did not include Williams.

The Carson campaign war chest, which had been flush with cash after solid fundraising quarters earlier in the race, began shrinking dramatically amid questions about how the money was being spent. Carson made further sweeping changes last month, cutting staff salaries and shrinking his traveling entourage.

“We had to get a much better check on the finances. I was appalled when I did a deep dive and saw what was going on. We saw that and stopped it,” Carson said in the Monday interview.

The mild-mannered candidate soon lashed out at individuals he accused of sabotaging his presidential bid, including rival Ted Cruz of Texas, whose campaign falsely circulated the idea that Carson was going to quit the race on the night of the Iowa caucuses.

He followed up a distant fourth-place showing in Iowa with last-place showings in New Hampshire and in South Carolina, a state he had once said would be a special focus. He polled poorly again in the 11 GOP primaries and caucuses Tuesday night.

When asked Monday whether he would ever reenter politics if he left the race, Carson chuckled at the prospect.

“I’m certainly not looking for something to do,” he said, adding that his plan after leaving medicine in 2013 was to retire to Palm Beach, Florida, with his wife.

“I’m not going to disappear,” he said. “But yes, if I didn’t think the country needed what we’re doing, I’d be there.”